Submarine sound transmitter



Novi 192 7. 1,649,113

H. C. HAYES SUBMARINE SOUND TRANSMITTER Filed Jan. 1924 Patented Nov. 15, 1927.

UNITED STATES PATENT OFFICE.

' SUBMARINE SOUND TRANSMITTER.

Application filed January 9, 1924. Serial No. 685,291.

My invention relates to submarine sound transmitters and more particularly to those termed oscillators, and has for an object the prevention of sound energy radiated into water from an oscillator returning and being absorbed by the skin of a vessel by providing a solid inertia backing in the region of the oscillator.

A further object is to increase signal strength without causing distortion or elongation of signal due to reverberation. With the above and other objects in view the invention consists in the construction, combination and arrangement of parts as will be hereinafter more fully described.

The usual manner of installing oscillators is to cut a hole through the vessels skin such that the oscillator diaphragm can project through the plating with its outer surface in contact with the surrounding medium and flush with the outside of the hull,-being secured in posit-ion by riveting to the vessels skin a flange carried by the oscillator.

it has been found, however, that with this installation a considerable part of the sound energy radiated traverses a short curved path and returns to the vessels hull., This is due to the fact there is not suificient inertia back of the plane of the oscillator to prevent the high compression waves from displacing the ships hull toward a region of pressure release within the hull. To remedy this defeet it has become customary to back up the vessels skin or plating surrounding the oscillator with a tank filled with liquid, this procedure having increased the strength of the signals considerably, but this gain has been offset by reverberation set up in the tankcausin distortion and elongation of the signals lnstead of permitting a desired rapid succession of short, clear cut signals.

By backing up the vessels skin with a solid inertia, such as lead or cement, all of the benefits of an inertia backing are obtained without the ill effects resulting from tank backin s. Much less sound energy builds up an resonates within the comparatively small volume of the solid inertia, as its coefiicient of reflection for those sound waves that meet the surface from the water outside the hull is greater than in the case of a tank, and the sound is, therefore, re- .flected and does not enter the inertia matethereto, a plate of lead surrounding the rial.

having a solid inertia backing may be best understood from the followin description and the accompanying drawing forming part of this specification. The figure shows a cross-section of a vessels hull having an oscillator mounted thereon. As the oscillator forms no part of the present invention, it is not illustrated in detail. Also, it W111 be understood that while but one side of a vessel is shown equipped with an oscillator and its backing, both sides may be so' provided, and if necessary a number may be mounted on each side.

In the drawing 5 indicates the skin of a vessel to which is secured an oscillator 6 by a flange 7. The region of the vessels skin adjacent to the oscillator is backed by an 111- ertia material 8, preferably lead or cement. The inertia backing may be placed inside or outside the vessel, but if outside the diaphragm is preferably so placed that it will be flush with the outer surface of the backmg.

It will be understood that the above description and accompanying drawing comprehend onl the general and preferred embodiment o my invention and that various changes in form, proportion and minor details of construction may be resorted to without departin' from the principle or sacrificing-any of t e advantages of this invention as claimed.

Having described my invention, I claim:

1. In combination a source of sound located in the hull of a vessel and attached thereto and solid annular means surrounding the source of sound having inertia coeflicients greater than that of the hull and that of the surrounding water.

2, In combination a source of sound located in the hull of a vessel and attached thereto, an annular plate of solid material thereto, an annular plate of solid material having a greater coeflicient of inertia than that of the section of the hull covered thereby and that of the surrounding water.

4. In combination, a source of sound located in the hull of a vessel and attached source of sound, said plate having suflicient source of sound and rigidly attached to the Weight to dam en the vibrations produced hull of the vessel, said plate having suflicient within the hul surrounding the source of weight to dampen the vibrations produced 10 sound. within the hull surrounding the source of 5 5. In combination, a. source of sound 10- sound.

cated in the hull of a. vessel and attached thereto, a. plate of lead surrounding the HARVEY G. HAYES. 

